1 //! Events are returned from various bits in the library which indicate some action must be taken
4 //! Because we don't have a built-in runtime, it's up to the client to call events at a time in the
5 //! future, as well as generate and broadcast funding transactions handle payment preimages and a
9 use ln::channelmanager::{PaymentPreimage, PaymentHash, PaymentSecret};
10 use chain::transaction::OutPoint;
11 use chain::keysinterface::SpendableOutputDescriptor;
12 use util::ser::{Writeable, Writer, MaybeReadable, Readable};
14 use bitcoin::blockdata::script::Script;
16 use secp256k1::key::PublicKey;
18 use std::time::Duration;
20 /// An Event which you should probably take some action in response to.
22 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
23 /// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
24 /// written as it makes no sense to respond to it after reconnecting to peers).
26 /// Used to indicate that the client should generate a funding transaction with the given
27 /// parameters and then call ChannelManager::funding_transaction_generated.
28 /// Generated in ChannelManager message handling.
29 /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
30 /// counterparty can steal your funds!
31 FundingGenerationReady {
32 /// The random channel_id we picked which you'll need to pass into
33 /// ChannelManager::funding_transaction_generated.
34 temporary_channel_id: [u8; 32],
35 /// The value, in satoshis, that the output should have.
36 channel_value_satoshis: u64,
37 /// The script which should be used in the transaction output.
38 output_script: Script,
39 /// The value passed in to ChannelManager::create_channel
42 /// Used to indicate that the client may now broadcast the funding transaction it created for a
43 /// channel. Broadcasting such a transaction prior to this event may lead to our counterparty
44 /// trivially stealing all funds in the funding transaction!
45 FundingBroadcastSafe {
46 /// The output, which was passed to ChannelManager::funding_transaction_generated, which is
47 /// now safe to broadcast.
48 funding_txo: OutPoint,
49 /// The value passed in to ChannelManager::create_channel
52 /// Indicates we've received money! Just gotta dig out that payment preimage and feed it to
53 /// ChannelManager::claim_funds to get it....
54 /// Note that if the preimage is not known or the amount paid is incorrect, you must call
55 /// ChannelManager::fail_htlc_backwards to free up resources for this HTLC.
56 /// The amount paid should be considered 'incorrect' when it is less than or more than twice
57 /// the amount expected.
59 /// The hash for which the preimage should be handed to the ChannelManager.
60 payment_hash: PaymentHash,
61 /// The "payment secret". This authenticates the sender to the recipient, preventing a
62 /// number of deanonymization attacks during the routing process.
63 /// As nodes upgrade, the invoices you provide should likely migrate to setting the
64 /// payment_secret feature to required, at which point you should fail_backwards any HTLCs
65 /// which have a None here.
66 /// Until then, however, values of None should be ignored, and only incorrect Some values
67 /// should result in an HTLC fail_backwards.
68 /// Note that, in any case, this value must be passed as-is to any fail or claim calls as
69 /// the HTLC index includes this value.
70 payment_secret: Option<PaymentSecret>,
71 /// The value, in thousandths of a satoshi, that this payment is for. Note that you must
72 /// compare this to the expected value before accepting the payment (as otherwise you are
73 /// providing proof-of-payment for less than the value you expected!).
76 /// Indicates an outbound payment we made succeeded (ie it made it all the way to its target
77 /// and we got back the payment preimage for it).
78 /// Note that duplicative PaymentSent Events may be generated - it is your responsibility to
79 /// deduplicate them by payment_preimage (which MUST be unique)!
81 /// The preimage to the hash given to ChannelManager::send_payment.
82 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
84 payment_preimage: PaymentPreimage,
86 /// Indicates an outbound payment we made failed. Probably some intermediary node dropped
87 /// something. You may wish to retry with a different route.
88 /// Note that duplicative PaymentFailed Events may be generated - it is your responsibility to
89 /// deduplicate them by payment_hash (which MUST be unique)!
91 /// The hash which was given to ChannelManager::send_payment.
92 payment_hash: PaymentHash,
93 /// Indicates the payment was rejected for some reason by the recipient. This implies that
94 /// the payment has failed, not just the route in question. If this is not set, you may
95 /// retry the payment via a different route.
96 rejected_by_dest: bool,
98 error_code: Option<u16>,
100 /// Used to indicate that ChannelManager::process_pending_htlc_forwards should be called at a
101 /// time in the future.
102 PendingHTLCsForwardable {
103 /// The minimum amount of time that should be waited prior to calling
104 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
105 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
106 /// now + 5*time_forwardable).
107 time_forwardable: Duration,
109 /// Used to indicate that an output was generated on-chain which you should know how to spend.
110 /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
111 /// counterparty spending them due to some kind of timeout. Thus, you need to store them
112 /// somewhere and spend them when you create on-chain transactions.
114 /// The outputs which you should store as spendable by you.
115 outputs: Vec<SpendableOutputDescriptor>,
119 impl Writeable for Event {
120 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
122 &Event::FundingGenerationReady { .. } => {
124 // We never write out FundingGenerationReady events as, upon disconnection, peers
125 // drop any channels which have not yet exchanged funding_signed.
127 &Event::FundingBroadcastSafe { ref funding_txo, ref user_channel_id } => {
129 funding_txo.write(writer)?;
130 user_channel_id.write(writer)?;
132 &Event::PaymentReceived { ref payment_hash, ref payment_secret, ref amt } => {
134 payment_hash.write(writer)?;
135 payment_secret.write(writer)?;
138 &Event::PaymentSent { ref payment_preimage } => {
140 payment_preimage.write(writer)?;
142 &Event::PaymentFailed { ref payment_hash, ref rejected_by_dest,
147 payment_hash.write(writer)?;
148 rejected_by_dest.write(writer)?;
150 error_code.write(writer)?;
152 &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
154 // We don't write the time_fordwardable out at all, as we presume when the user
155 // deserializes us at least that much time has elapsed.
157 &Event::SpendableOutputs { ref outputs } => {
159 (outputs.len() as u64).write(writer)?;
160 for output in outputs.iter() {
161 output.write(writer)?;
168 impl MaybeReadable for Event {
169 fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
170 match Readable::read(reader)? {
172 1u8 => Ok(Some(Event::FundingBroadcastSafe {
173 funding_txo: Readable::read(reader)?,
174 user_channel_id: Readable::read(reader)?,
176 2u8 => Ok(Some(Event::PaymentReceived {
177 payment_hash: Readable::read(reader)?,
178 payment_secret: Readable::read(reader)?,
179 amt: Readable::read(reader)?,
181 3u8 => Ok(Some(Event::PaymentSent {
182 payment_preimage: Readable::read(reader)?,
184 4u8 => Ok(Some(Event::PaymentFailed {
185 payment_hash: Readable::read(reader)?,
186 rejected_by_dest: Readable::read(reader)?,
188 error_code: Readable::read(reader)?,
190 5u8 => Ok(Some(Event::PendingHTLCsForwardable {
191 time_forwardable: Duration::from_secs(0)
194 let outputs_len: u64 = Readable::read(reader)?;
195 let mut outputs = Vec::new();
196 for _ in 0..outputs_len {
197 outputs.push(Readable::read(reader)?);
199 Ok(Some(Event::SpendableOutputs { outputs }))
201 _ => Err(msgs::DecodeError::InvalidValue)
206 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
207 /// broadcast to most peers).
208 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
210 pub enum MessageSendEvent {
211 /// Used to indicate that we've accepted a channel open and should send the accept_channel
212 /// message provided to the given peer.
214 /// The node_id of the node which should receive this message
216 /// The message which should be sent.
217 msg: msgs::AcceptChannel,
219 /// Used to indicate that we've initiated a channel open and should send the open_channel
220 /// message provided to the given peer.
222 /// The node_id of the node which should receive this message
224 /// The message which should be sent.
225 msg: msgs::OpenChannel,
227 /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
229 /// The node_id of the node which should receive this message
231 /// The message which should be sent.
232 msg: msgs::FundingCreated,
234 /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
236 /// The node_id of the node which should receive this message
238 /// The message which should be sent.
239 msg: msgs::FundingSigned,
241 /// Used to indicate that a funding_locked message should be sent to the peer with the given node_id.
243 /// The node_id of the node which should receive these message(s)
245 /// The funding_locked message which should be sent.
246 msg: msgs::FundingLocked,
248 /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
249 SendAnnouncementSignatures {
250 /// The node_id of the node which should receive these message(s)
252 /// The announcement_signatures message which should be sent.
253 msg: msgs::AnnouncementSignatures,
255 /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
256 /// message should be sent to the peer with the given node_id.
258 /// The node_id of the node which should receive these message(s)
260 /// The update messages which should be sent. ALL messages in the struct should be sent!
261 updates: msgs::CommitmentUpdate,
263 /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
265 /// The node_id of the node which should receive this message
267 /// The message which should be sent.
268 msg: msgs::RevokeAndACK,
270 /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
272 /// The node_id of the node which should receive this message
274 /// The message which should be sent.
275 msg: msgs::ClosingSigned,
277 /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
279 /// The node_id of the node which should receive this message
281 /// The message which should be sent.
284 /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
285 SendChannelReestablish {
286 /// The node_id of the node which should receive this message
288 /// The message which should be sent.
289 msg: msgs::ChannelReestablish,
291 /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
292 /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
294 /// Note that after doing so, you very likely (unless you did so very recently) want to call
295 /// ChannelManager::broadcast_node_announcement to trigger a BroadcastNodeAnnouncement event.
296 /// This ensures that any nodes which see our channel_announcement also have a relevant
297 /// node_announcement, including relevant feature flags which may be important for routing
298 /// through or to us.
299 BroadcastChannelAnnouncement {
300 /// The channel_announcement which should be sent.
301 msg: msgs::ChannelAnnouncement,
302 /// The followup channel_update which should be sent.
303 update_msg: msgs::ChannelUpdate,
305 /// Used to indicate that a node_announcement should be broadcast to all peers.
306 BroadcastNodeAnnouncement {
307 /// The node_announcement which should be sent.
308 msg: msgs::NodeAnnouncement,
310 /// Used to indicate that a channel_update should be broadcast to all peers.
311 BroadcastChannelUpdate {
312 /// The channel_update which should be sent.
313 msg: msgs::ChannelUpdate,
315 /// Broadcast an error downstream to be handled
317 /// The node_id of the node which should receive this message
319 /// The action which should be taken.
320 action: msgs::ErrorAction
322 /// When a payment fails we may receive updates back from the hop where it failed. In such
323 /// cases this event is generated so that we can inform the router of this information.
324 PaymentFailureNetworkUpdate {
325 /// The channel/node update which should be sent to router
326 update: msgs::HTLCFailChannelUpdate,
330 /// A trait indicating an object may generate message send events
331 pub trait MessageSendEventsProvider {
332 /// Gets the list of pending events which were generated by previous actions, clearing the list
334 fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
337 /// A trait indicating an object may generate events
338 pub trait EventsProvider {
339 /// Gets the list of pending events which were generated by previous actions, clearing the list
341 fn get_and_clear_pending_events(&self) -> Vec<Event>;